The File-Sync cloud based services which NovaBACKUP currently works with, starting with version 16.5, each have their own limits for the size of EACH individual file that can be stored on those file-sync services (on the cloud).

Since NovaBACKUP creates a single large file as your backup set (.NBD file) to then tell OneDrive, Dropbox, Google Drive to store in their cloud, there is certainly a potential that the backup set will be too large to fit within the file sharing services own limitations for the size that each file that you are attempting to store to those services.

How to target Cloud Storage as your Backup Destination:

On the Backup or Copy tabs select [Backup To...] at the bottom left of the screen.

As the backup destination, choose the location your cloud provider synchronizes the data to on your machine. For Backups, give a media name for the output file.

Once your backup completes, the Cloud Provider will synchronize the backup to their storage.

For instance, OneDrive has a 10GB per file size limit which a typical NovaBACKUP produced backup set can easily exceed in most cases.

Microsoft OneDrive currently has a 10GB per file size limit, meaning the typical NovaBACKUP backup set that attempts to be stored to OneDrive will fail to sync the file that we create, the .NBD file, to OneDrive if the file is over 10GB which in most cases it would be for the typical amount of data that a backup set would be selected to backup.

Google Drive has a maximum amount of data that can be transferred in a single day imposed upon their Sync client, this amount is 750 GB. After you've uploaded 750 GB in 1 day, you'll be blocked from uploading additional files that day. See here for more info.

Dropbox used to have no size limit specified per file but now have a 20GB/file size limit instituted for each file, be careful of this.

IDriveSync supports sync (up to 5 computers) and sharing (up to 50 accounts) of files of all sizes and types. With a free account you can sync up to 5 GB of data and for as little as $4.95 / month, you can avail unlimited sync storage.